The present invention relates to an apparatus for measuring constituents of sugar beets during harvesting or in the field after harvesting. Additionally, the present invention relates to a method and apparatus using a near-infrared (NIR) spectrometer and optical analysis in combination with a sugar beet harvester/defoliator for real-time quality analysis of sugar beets. This invention may also be used for determination of sugar content of other sugar-containing agricultural products such as grapes, grapefruits, oranges, or other fruits.
Food producers and others often analyze the major constituents, such as sugar content and moisture, of certain agricultural products including sugar beets, grapes, and grapefruits. This analysis can be used for developing new hybrid species of crops. Moreover, with the advent of precision farming, it is desirable to obtain information relating to quality, such as sugar content, of an agricultural product being harvested along with yield (quantity) information. At present, technologies are available to determine the sugar content of sugar-containing agricultural products in laboratory conditions or in a processing plant. However, it is desirable to obtain quality information during harvesting in order to manage and plan crop production for consistent quality. Therefore, a need exists for a sensor with or without a harvester to operate in a field environment and which is also capable of determining sugar content in real-time, near real-time, or in a quick manner.
A device consistent with the present invention is used for determining sugar content of an agricultural product while being harvested or in the field condition. The device includes a sample preparation mechanism attached to a harvester/defoliator for use with a received agricultural product during harvesting to create an exposed sample of the agricultural product. An illumination chamber radiates the exposed sample, and a sensor receives radiation from the exposed sample. A spectrometer converts the radiation into a corresponding spectral signal, and a computer receives the spectral signal and processes it to determine an indication of sugar content of the agricultural product.
A method consistent with the present invention processes a spectral signal to predict sugar content of an agricultural product. The method includes receiving a light signal from an agricultural product and converting the light signal into a spectral signal. The spectral signal is digitized to produce a plurality of data points, which are then processed using dark signal values and a reference signal value to produce a plurality of normalized data points. The normalized data points have values related to sugar content of the agricultural product and can be used to predict the sugar content using various prediction techniques.